This invention relates to an arrangement for adjusting a mounting part on a carrier in a statically determined position which can be adjusted in three axes in a rotatory and translatory manner with respect to the carrier. At least three adjusting units are arranged in an offset manner with respect to one another between the carrier and the mounting part. Each adjusting unit comprises two connecting parts which can be translatorily adjusted with respect to one another in two axes and is constructed to be freely movable rotatorily in three axes and translatorily in one axis in a sloped manner to the adjusting plane of the connecting parts.
In the field of space operations, arrangements of this type are known, e.g., "Space Shuttle Accommodation Handbook", Vol. XIV. The arrangements permit an anchoring of a useful load which can be adjusted in all six degrees of freedom in the load bay of a spacecraft by means of fastening units. The fastening units are arranged in the manner of a three-point suspension and each comprise a combined freely movable ball joint slide connection with slide pins rigidly fastened to the useful load as well as a cross slide arrangement which can be adjusted in a translatory manner in two axes and acts between the ball joint and the load bay wall. Because of their relatively low constructive stiffness, adjusting arrangements of this type must be produced from massive components with a view to a precise fixing of the mounting part in the respective adjusting position. This requires expenditures of space and weight which are unacceptable, particularly in space operations.
It is therefore an object of the invention to construct an arrangement of the above-mentioned type in such a manner that it has a high constructive stiffness and, in a constructionally simple, weight and space saving manner, permits a precise adjusting of the mounting part with positional stability with respect to the carrier.
According to the present invention, this object is achieved by an arrangement for adjusting a mounting part on a carrier in a statically determined position which can be adjusted in three axes in a rotatory and translatory manner with respect to the carrier. At least three adjusting units are arranged in an offset manner with respect to one another between the carrier and the mounting part. Each adjusting unit comprises two connecting parts which can be translatorily adjusted with respect to one another in two axes and is constructed to be freely movable rotatorily in three axes and translatorily in one axis in a sloped manner to the adjusting plane of the connecting parts. The two connecting parts are adjustably coupled with one another in two axes by means of a double disk arrangement. The double disk arrangement comprises a primary disk which is disposed in the adjusting plane of the connecting parts on one connecting part so that the rotating position can be adjusted, add a secondary disk which is enclosed by the primary disk and is disposed so that its rotating position on the primary disk can be adjusted about an axis (B) which is eccentric to its axis of rotation (A). The other connecting part is arranged on the secondary disk at a distance (a) from the axis of rotation (B) of the secondary disk.
According to the present invention, the adjusting movements of the mounting part in all six degrees of freedom are caused exclusively by rotationally positionable disk elements which interact with one another in pairs. Because of the homogeneous inherent stiffness which is high in the direction of their surface dimension and because of their arrangement in the adjusting plane of the connecting parts, the disk elements ensure a highly load-stable coupling of the mounting part and the carrier and an extremely flat construction with low expenditures of space and weight consisting of a few structural elements which are easy to manufacture, with the additional kinematic advantage that, in the case of a rotation of the disk elements without any reversal of the rotating direction automatically, a reversing translatory adjusting movement takes place between the connecting parts of the individual adjusting units.
With a view to an additional constructional simplification and load-stable bearing, the primary and the secondary disk of the double disk arrangement are preferably, by means of a bearing device which in each case surrounds the outer circumference of the disks in a ring-shaped manner, arranged to be mutually rotatable or rotatable on the one connecting part. The bearing points which surround the outer edge of the disks are expediently constructed to be form-locking on both sides, whereby the stiffness and the adjusting precision of the double disk arrangement are increased further. For the same reason, the primary and the secondary disk are preferably arranged in a coplanar manner with respect to one another.
In order to be able to adjust the connecting parts relative to one another on any arbitrary point within an area of a complete circle by means of the rotational disk arrangement, it is recommended to select the distance between the axis of rotation of the secondary disk and the connecting part arranged on it essentially of the same size as the eccentricity between the axes of rotation of the disks.
In order to be able to use the double disk arrangement several times for adjusting purposes, this double disk arrangement can be removed preferably in the adjusting condition and can be exchanged for an end-mounted fastening unit which is manufactured with precise measurements according to the relative position of the connecting parts.
However, in a particularly preferred development of the invention, the adjusting units remain between the mounting part and the carrier for the final fastening, in which case the double disk arrangements are non-rotatably locked in the adjusting position. The locking is very advantageously constructed to be releasable so that in the mounted condition, the double disk arrangements permit a readjusting of the mounting part with respect to the carrier. In a particularly preferred manner, the double disk arrangements are driven by a motor so that, the rotating positions can be adjusted and so that the adjusting units, without any problems, can be adjusted and readjusted in a remote-controlled manner in a mounting position that is difficult to access as well as by radio, for example, in orbit.
With a view to a particularly space-saving construction that is easy to manufacture, the one connecting part is preferably fastened directly on the carrier in a rigid manner, while the other connecting part is constructed as a combined ball joint slide connection with a sliding pin which is rigidly fastened on the mounting part.
The slide shafts of the individual adjusting units which are in each case provided for the free translatory movement are expediently aligned with a common intersecting point, whereby in a very simple manner a suspension of the mounting part on the carrier is achieved that is free of thermal stress.
Because of the relationship between the rotating position changes of the individual primary and secondary disks which kinematically is generally complicated and because of the resulting rotatory and translatory movements of the mounting part in a reference system of coordinates fixed on the carrier, it is finally recommended to correlate the rotating position adjusting movements of the primary and secondary disks of the adjusting units in a computer-assisted manner.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.